1. Field of the Invention
This embodiment relates to a lighting device capable of implementing rear light distribution.
2. Description of the Related Art
Here, related arts to the present invention will be provided and has not necessarily been to publicly known.
Nowadays, with the improvement of residential environment, indoor lighting is now being advanced from white lighting such as an existing fluorescent lamp, a halogen lamp or the like to luxurious interior lighting by representing indoor lighting colors, i.e., color temperatures in various ways. In particular, efforts are now being constantly made to representatively apply a light emitting diode (LED) light source device to the advanced interior lighting.
The LED has a small size and good efficiency and is capable of emitting light having an apparent color. Since the LED is a kind of a semiconductor device, the LED is less expected to be damaged, has excellent initial drive characteristic and impact-resistance, and is resistant to repetition like on/off lighting. For these reasons, the LED is now being widely used in various indicators and a variety of light sources. Moreover, R, G and B LEDs having ultra high luminance and high efficiency are now being developed respectively, and thus, a large-screen LED display using the LEDs is commercialized and widely used.
An angle at which light is emitted from a conventional LED lighting device is generally maintained from approximately 90° to 140°. Therefore, an interval at which a plurality of LEDs are disposed and mounted on a printed circuit board is set by the light emission angle. That is, the interval must be set such that the LEDs are densely disposed in order to prevent a dark zone from occurring due to the blocking of the light which is emitted from the LED and is incident on a light transmissive cover. Therefore, a fairly large number of the LEDs are required. Moreover, in order that the dark zone is removed by overlapping the light emitted from an LED with light emitted from another LED adjacent to the LED in a certain section, the light transmissive cover and the LED must be disposed at a large interval.
Accordingly, the conventional lighting device requires a large number of the LEDs and high manufacturing cost. The large interval between the light transmissive cover and the LED increases the thickness of the conventional lighting device, which makes the conventional lighting device become larger.